The present invention relates to tunable fiber optic connectors for use in optical fiber signal transmission systems, and to methods for assembling such fiber optic connectors.
Fiber optic cables are used in the telecommunication industry to transmit light signals in high speed data and communication systems. A standard fiber optic cable includes a fiber with an inner light transmitting optical core. Surrounding the fiber typically is a reinforcing layer and an outer protective casing.
A fiber terminates at a fiber optic connector. Connectors are frequently used to non-permanently connect and disconnect optical elements in a fiber optic transmission system. There are many different fiber optic connector types. Some of the more common connectors are FC and SC connectors. Other types of connectors include ST and D4-type connectors.
A typical SC fiber optic connector includes a housing having a front end positioned opposite from a rear end. The front end of the SC connector housing is commonly configured to be inserted within an adapter. An example adapter is shown in U.S. Pat. No. 5,317,663, the disclosure of which is incorporated by reference. The SC connector typically further includes a ferrule that is positioned within the front and rear ends of the housing, and adjacent the front end. The ferrule is axially moveable relative to the housing, and is spring biased toward the front of the connector. The fiber optic cable has an end that is stripped. The stripped end includes a bare fiber that extends into the connector and through the ferrule.
A connector, such as the connector described above, is mated to another connector within an adapter like the adapter of U.S. Pat. No. 5,317,663. A first connector is received within the front portion of the adapter, and a second fiber is received within the rear portion of the adapter. When two connectors are fully received within an adapter, the ferrules (and hence the fibers internal to the ferrule) contact or are in close proximity to each other to provide for signal transmission between the fibers.
Signal losses within a system often occur within the connection between two optical fiber cores. Due to manufacturing tolerances of the ferrule outer diameter to inner diameter concentricity, ferrule inner diameter hole size and fiber outer diameter, and fiber core to fiber outer diameter concentricity, when the fiber is inserted into the ferrule the core of a fiber may not and typically does not end up perfectly centered relative to the ferrule outer diameter. If one or both of the fibers are off center, when they are connected within an adapter, the fibers will not be aligned and thus there will be a signal loss when the signal is transmitted between the two fibers. It is therefore desirable to have a tunable connector that can provide for optimal alignment with another connector so as to minimize signal loss.
One aspect of the present invention relates to a fiber optic connector. The connector includes a ferrule that is retainably engaged within a hub. The connector further includes a rear housing and a front housing. The rear housing is sized to receive and rotationally retain the hub. The front housing has a bore that receives and engages the exterior surface of the rear housing. The front and rear housing include engagement members that allow the rear housing to be retained within the front housing and rotated relative to the front housing between discrete positions.
Another aspect of the present invention relates to a method for assembling a fiber optic connector. The method includes providing a ferrule retainably engaging a hub. This assembly is then positioned within the bore of a rear housing with the hub rotationally retained within the bore. Next, the rear housing is inserted into the bore of a front housing, and the rear housing is then rotated within the front housing between discrete positions.
A variety of advantages of the invention will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practicing the invention. It is to be understood that both the foregoing general description and the following detailed description are explanatory only and are not restrictive of the invention as claimed.